Two-scale thermomechanical damage model for dynamic shear failure in brittle solids

Abstract

A coupled thermo-mechanical damage approach for dynamic shear failure in brittle solids is proposed in the present contribution. The model is constructed by asymptotic homogenization from microstructures with dynamically evolving microcracks, in mode II, with unilateral contact and friction conditions on their lips. Crack-tip and frictional heating effects assumed at the small-scale give rise to distributed heat sources in the macroscopic temperature equation and specific dissipation terms in the upscaled damage law. The analysis of the effective thermomechanical response of the model reveals strain-rate and size effects and the influence of friction and growth of microcracks on the macroscopic thermal evolutions.